Method for transmitting and receiving control information including configuration information for transmission and reception in communication system supporting vehicle-to-everything communication and apparatus for the same

ABSTRACT

An operation method of a first communication node in a vehicle-to-everything (V2X) communication system may include: receiving, by the first communication node, control information including resource allocation information from a second communication node; receiving, by the first communication node, data from the second communication node through a radio resource indicated by the resource allocation information included in the control information; generating, by the first communication node, sidelink control information (SCI) including reception configuration information indicating the radio resource used for transmission of the data by the second communication node based on the resource allocation information; and transmitting, by the first communication node, the SCI to a third communication node.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. ProvisionalPatent Application No. 62/623,758, filed on Jan. 30, 2018, U.S.Provisional Patent Application No. 62/654,827, filed on Apr. 9, 2018,and Korean Patent Application No. 10-2019-0003452 filed on Jan. 10, 2019in the Korean Intellectual Property Office (KIPO), the entire contentsof each of which are incorporated herein by reference.

BACKGROUND 1. Technical Field

The present disclosure relates generally to vehicle-to-everything (V2X)communication, and more specifically, to methods and apparatuses fortransmitting and receiving control information including configurationinformation for transmission/reception in a V2X communication system.

2. Related Art

Various systems have been developed for processing of wireless data suchas the fourth-generation (4G) communication system (e.g., Long TermEvolution (LTE) communication system or LTE-Advanced (LTE-A)communication system) and the fifth-generation (5G) communication system(e.g., New Radio (NR) communication system), which uses a frequency bandhigher than the frequency band of the 4G communication system. The 5Gcommunication system can support Enhanced Mobile Broadband (eMBB)communications, Ultra-Reliable and Low-Latency communications (URLLC),massive Machine Type Communications (mMTC), and the like.

The 4G communication system and 5G communication system can supportVehicle-to-Everything (V2X) communications. The V2X communicationssupported in a cellular communication system, such as the 4Gcommunication system, the 5G communication system, and the like, may bereferred to as “Cellular-V2X (C-V2X) communications.” The V2Xcommunications (e.g., C-V2X communications) may includeVehicle-to-Vehicle (V2V) communications, Vehicle-to-Infrastructure (V2I)communications, Vehicle-to-Pedestrian (V2P) communication,Vehicle-to-Network (V2N) communication, and the like.

In many cellular communication systems, the V2X communications (e.g.,C-V2X communications) may be performed based on “sidelink” communicationtechnologies (e.g., Proximity-based Services (ProSe) communicationtechnology, Device-to-Device (D2D) communication technology, or thelike). For example, sidelink channels for vehicles participating in V2Vcommunications can be established, and communications between thevehicles can be performed using the sidelink channels.

In cellular communication systems supporting V2X communications (e.g.,C-V2X communication), a terminal located in a vehicle may perform theV2X communications using a resource allocated by a base station or aresource arbitrarily selected within a resource pool configured by thebase station. The terminal may measure a channel busy ratio (CBR)periodically or when a preset event occurs, and may transmit ameasurement result of the CBR to the base station. The base station mayreceive the measurement result of the CBR from the terminal, andidentify a channel congestion based on the measurement result of theCBR. The base station may also adjust transmission parameters (e.g.,modulation and coding scheme (MCS), maximum transmission power, range ofretransmission counts per transport block (TB), etc.) based on channelcongestion.

Meanwhile, in the V2X sidelink communication, a first terminal maytransmit sidelink control information (SCI) including resourceallocation information to a second terminal, and then may use a resourcescheduled by the SCI to transmit data to the second terminal. The SCIand the data may be transmitted in the same subframe. Alternatively,when the SCI is transmitted in a subframe #n, the data may betransmitted in a subframe #(n+k). Here, n may be an integer greater thanor equal to 0, and k may be an integer greater than or equal to 1.

Independently of the V2X sidelink communication between the firstterminal and the second terminal, a third terminal may transmit an SCIand data to the first terminal based on the V2X sidelink communicationscheme. The scheduling information included in the SCI of the thirdterminal may indicate that data is to be transmitted from the thirdterminal to the first terminal according to a predetermined periodicity.The SCI of the third terminal may not be received at the secondterminal.

When data to be transmitted from the second terminal to the firstterminal is generated, the second terminal may transmit an SCI and thedata to the first terminal based on the V2X sidelink communicationscheme. Problematically, a radio resource occupied by a V2X sidelinksignal transmitted from the second terminal to the first terminal may beoverlapped with a radio resource occupied by a V2X sidelink signaltransmitted from the third terminal to the first terminal. Therefore,the first terminal may not receive both the V2X sidelink signal of thesecond terminal and the V2X sidelink signal of the third terminal.

SUMMARY

Accordingly, embodiments of the present disclosure provide a method andan apparatus for transmitting and receiving sidelink control information(SCI) including configuration information for transmission/reception ina V2X communication system.

According to embodiments of the present disclosure, an operation methodof a first communication node located in a vehicle supporting avehicle-to-everything (V2X) communication system may include: receiving,by the first communication node, control information including resourceallocation information from a second communication node; receiving, bythe first communication node, data from the second communication nodethrough a radio resource indicated by the resource allocationinformation included in the control information; generating, by thefirst communication node, sidelink control information (SCI) includingreception configuration information indicating the radio resource usedfor transmission of the data by the second communication node based onthe resource allocation information; and transmitting, by the firstcommunication node, the SCI to a third communication node.

The SCI may further include a format index indicating whether the SCIincludes the reception configuration information.

The reception configuration information may include at least one ofinformation indicating a transmission cycle of the data transmitted bythe second communication node, information indicating a time resourcethrough which the data is transmitted by the second communication node,and information indicating a frequency resource through which the datais transmitted by the second communication node.

The reception configuration information may further include informationindicating a valid period during which data transmission from the thirdcommunication node to the first communication node is restricted.

The operation method may further include transmitting, by the firstcommunication node, a first message to the second communication node,the first message including information indicating that the firstcommunication node operates as a relay or a coordinator; and receiving,by the first communication node, a second message from the secondcommunication node, the second message including information instructingto transmit the SCI including the reception configuration information.The first communication node may transmit the SCI in response toreceiving the second message.

The first message and the second message may be transmitted and receivedaccording to a connection establishment procedure between the firstcommunication node and the second communication node.

The operation method may further include transmitting, by the firstcommunication node, a third message to the third communication node, thethird message including information indicating that the SCI includingthe reception configuration information is to be transmitted by thefirst communication node. The first communication node may transmit theSCI after the third message is transmitted.

The third message may be a radio resource control (RRC) message, amessage including a medium access control (MAC) control element (CE), ora message according to a PC5 signaling protocol.

Furthermore, in accordance with embodiments of the present disclosure,an operation method of a first communication node located in a vehiclesupporting a vehicle-to-everything (V2X) communication system mayinclude: receiving, by the first communication node, control informationincluding resource allocation information from a second communicationnode; receiving, by the first communication node, first data from thesecond communication node through a radio resource indicated by theresource allocation information included in the control information;generating, by the first communication node, reception configurationinformation indicating the radio resource used for transmission of thefirst data based on the resource allocation information; generating, bythe first communication node, transmission configuration information forsecond data to be transmitted to a third communication node; andtransmitting, by the first communication node, sidelink controlinformation (SCI) including the reception configuration information andthe transmission configuration information to the third communicationnode.

The SCI may further include a format index indicating whether the SCIincludes the reception configuration information and the transmissionconfiguration information.

The reception configuration information includes at least one ofinformation indicating a transmission cycle of the first data,information indicating a time resource through which the first data istransmitted, and information indicating a frequency resource throughwhich the first data is transmitted.

The reception configuration information may include informationindicating a valid period during which data transmission from the thirdcommunication node to the first communication node is restricted.

The transmission configuration information may include schedulinginformation used for transmission and reception of the second data.

The operation method may further include transmitting, by the firstcommunication node, to the second communication node a first messageincluding information requesting permission of transmission of the SCIincluding the reception configuration information; and receiving, by thefirst communication node, from the second communication node a secondmessage including information instructing the first communication nodeto transmit the SCI including the reception configuration information.The first communication node may transmit the SCI in response toreceiving the second message.

The operation method may further include transmitting, by the firstcommunication node, a third message to the third communication node, thethird message including information indicating that the SCI includingthe reception configuration information is to be transmitted by thefirst communication node. The first communication node may transmit theSCI after the third message is transmitted.

The third message may be a radio resource control (RRC) message, amessage including a medium access control (MAC) control element (CE), ora message according to a PC5 signaling protocol.

Furthermore, in accordance with embodiments of the present disclosure,an operation method of a first communication node located in a vehiclesupporting a vehicle-to-everything (V2X) communication system mayinclude: receiving, by the first communication node, sidelink controlinformation (SCI) from a second communication node; identifying, by thefirst communication node, a format index included in the SCI; andobtaining, by the first communication node, reception configurationinformation included in the SCI when the format index indicates that theSCI includes the reception configuration information. The receptionconfiguration information may include information indicating a radioresource allocated for first data transmitted from a third communicationnode to the second communication node.

The operation method may further include, when the SCI includesscheduling information for second data to be transmitted from the secondcommunication node to the first communication node, receiving, by thefirst communication node, the second data from the second communicationnode based on the scheduling information.

The operation method may further include, when the receptionconfiguration information further includes information indicating avalid period during which transmission of third data is restricted,transmitting, by the first communication node, the third data to thesecond communication node after the valid period expires.

The operation method may further include receiving, by the firstcommunication node, from the second communication node a messageincluding information indicating that the SCI including the receptionconfiguration information is to be transmitted by the firstcommunication node. The first communication node may receive the SCI inresponse to receiving the message.

According to the embodiments of the present disclosure, a first terminalcan generate a sidelink control information (SCI) including transmissionconfiguration information and reception configuration information, andcan transmit the generated SCI to a second terminal. The transmissionconfiguration information may include resource allocation informationfor data to be transmitted from the first terminal to the secondterminal, and the reception configuration information may includeresource allocation information for data to be transmitted from a thirdterminal to the first terminal (or, from a base station to the firstterminal). The second terminal can receive the SCI from the firstterminal, and obtain the reception configuration information as well asthe transmission configuration information from the received SCI.

When data to be transmitted from the second terminal to the firstterminal is generated, the second terminal can transmit the SCI and thedata to the first terminal in consideration of the resource allocationinformation indicated by the reception configuration information. Inthis case, a V2X sidelink signal transmitted from the second terminal tothe first terminal may not collide with a V2X sidelink signaltransmitted from the third terminal to the first terminal (or, adownlink signal from a base station to the first terminal). Therefore,the first terminal can receive both the V2X sidelink signal of thesecond terminal and the V2X sidelink signal of the third terminal (or,the downlink signal of the base station). As a result, the performanceof the V2X communication system can be improved.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the present disclosure will become more apparent bydescribing in detail embodiments of the present disclosure withreference to the accompanying drawings, in which:

FIG. 1 is a conceptual diagram illustrating V2X communication scenarios;

FIG. 2 is a conceptual diagram illustrating embodiments of a cellularcommunication system;

FIG. 3 is a conceptual diagram illustrating embodiments of acommunication node constituting a cellular communication system;

FIG. 4 is a block diagram illustrating embodiments of a user planeprotocol stack of an UE performing sidelink communication;

FIG. 5 is a block diagram illustrating a first embodiment of a controlplane protocol stack of an UE performing sidelink communication;

FIG. 6 is a block diagram illustrating a second embodiment of a controlplane protocol stack of an UE performing sidelink communication;

FIG. 7 is a conceptual diagram illustrating a first embodiment of a V2Xcommunication system;

FIG. 8 is a conceptual diagram illustrating a second embodiment of a V2Xcommunication system;

FIG. 9 is a sequence chart illustrating a first embodiment of a methodfor triggering an SCI transmission/reception procedure in a V2Xcommunication system; and

FIG. 10 is a sequence chart illustrating a first embodiment of an SCItransmission and reception method in a V2X communication system.

It should be understood that the above-referenced drawings are notnecessarily to scale, presenting a somewhat simplified representation ofvarious preferred features illustrative of the basic principles of thedisclosure. The specific design features of the present disclosure,including, for example, specific dimensions, orientations, locations,and shapes, will be determined in part by the particular intendedapplication and use environment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Embodiments of the present disclosure are disclosed herein. However,specific structural and functional details disclosed herein are merelyrepresentative for purposes of describing embodiments of the presentdisclosure. Thus, embodiments of the present disclosure may be embodiedin many alternate forms and should not be construed as limited toembodiments of the present disclosure set forth herein.

Accordingly, while the present disclosure is capable of variousmodifications and alternative forms, specific embodiments thereof areshown by way of example in the drawings and will herein be described indetail. It should be understood, however, that there is no intent tolimit the present disclosure to the particular forms disclosed, but onthe contrary, the present disclosure is to cover all modifications,equivalents, and alternatives falling within the spirit and scope of thepresent disclosure. Like numbers refer to like elements throughout thedescription of the figures.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of the present disclosure. Asused herein, the term “and/or” includes any and all combinations of oneor more of the associated listed items.

It will be understood that when an element is referred to as being“connected” or “coupled” to another element, it can be directlyconnected or coupled to the other element or intervening elements may bepresent. In contrast, when an element is referred to as being “directlyconnected” or “directly coupled” to another element, there are nointervening elements present. Other words used to describe therelationship between elements should be interpreted in a like fashion(i.e., “between” versus “directly between,” “adjacent” versus “directlyadjacent,” etc.).

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the presentdisclosure. As used herein, the singular forms “a,” “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises,” “comprising,” “includes” and/or “including,” when usedherein, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this present disclosure belongs.It will be further understood that terms, such as those defined incommonly used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand will not be interpreted in an idealized or overly formal senseunless expressly so defined herein.

It is understood that the term “vehicle” or “vehicular” or other similarterm as used herein is inclusive of motor vehicles in general such aspassenger automobiles including sports utility vehicles (SUV), buses,trucks, various commercial vehicles, watercraft including a variety ofboats and ships, aircraft, and the like, and includes hybrid vehicles,electric vehicles, plug-in hybrid electric vehicles, hydrogen-poweredvehicles and other alternative fuel vehicles (e.g., fuels derived fromresources other than petroleum). As referred to herein, a hybrid vehicleis a vehicle that has two or more sources of power, for example bothgasoline-powered and electric-powered vehicles.

Additionally, it is understood that one or more of the below methods, oraspects thereof, may be executed by at least one control unit. The term“control unit” may refer to a hardware device that includes a memory anda processor. The memory is configured to store program instructions, andthe processor is specifically programmed to execute the programinstructions to perform one or more processes which are describedfurther below. The control unit may control operation of units, modules,parts, or the like, as described herein. Moreover, it is understood thatthe below methods may be executed by an apparatus (e.g., communicationnode) comprising the control unit in conjunction with one or more othercomponents, as would be appreciated by a person of ordinary skill in theart.

Furthermore, the control unit of the present disclosure may be embodiedas non-transitory computer readable media containing executable programinstructions executed by a processor, controller or the like. Examplesof the computer readable mediums include, but are not limited to, ROM,RAM, compact disc (CD)-ROMs, magnetic tapes, floppy disks, flash drives,smart cards and optical data storage devices. The computer readablerecording medium can also be distributed throughout a computer networkso that the program instructions are stored and executed in adistributed fashion, e.g., by a telematics server or a Controller AreaNetwork (CAN).

Hereinafter, embodiments of the present disclosure will be described ingreater detail with reference to the accompanying drawings. In order tofacilitate general understanding in describing the present disclosure,the same components in the drawings are denoted with the same referencesigns, and repeated description thereof will be omitted.

FIG. 1 is a conceptual diagram illustrating V2X communication scenarios.

As shown in FIG. 1, the V2X communications may includeVehicle-to-Vehicle (V2V) communications, Vehicle-to-Infrastructure (V2I)communications, Vehicle-to-Pedestrian (V2P) communications,Vehicle-to-Network (V2N) communications, and the like. The V2Xcommunications may be supported by a cellular communication system(e.g., a cellular communication system 140), and the V2X communicationssupported by the cellular communication system 140 may be referred to as“Cellular-V2X (C-V2X) communications.” Here, the cellular communicationsystem 140 may include the 4G communication system (e.g., LTEcommunication system or LTE-A communication system), the 5Gcommunication system (e.g., NR communication system), and the like.

The V2V communications may include communications between a firstvehicle 100 (e.g., a communication node located in the vehicle 100) anda second vehicle 110 (e.g., a communication node located in the vehicle110). Various driving information such as velocity, heading, time,position, and the like may be exchanged between the vehicles 100 and 110through the V2V communications. For example, autonomous driving (e.g.,platooning) may be supported based on the driving information exchangedthrough the V2V communications. The V2V communications supported in thecellular communication system 140 may be performed based on “sidelink”communication technologies (e.g., ProSe and D2D communicationtechnologies, and the like). In this case, the communications betweenthe vehicles 100 and 110 may be performed using at least one sidelinkchannel established between the vehicles 100 and 110.

The V2I communications may include communications between the firstvehicle 100 (e.g., the communication node located in the vehicle 100)and an infrastructure (e.g., road side unit (RSU)) 120 located on aroadside. The infrastructure 120 may also include a traffic light or astreet light which is located on the roadside. For example, when the V2Icommunications are performed, the communications may be performedbetween the communication node located in the first vehicle 100 and acommunication node located in a traffic light. Traffic information,driving information, and the like may be exchanged between the firstvehicle 100 and the infrastructure 120 through the V2I communications.The V2I communications supported in the cellular communication system140 may also be performed based on sidelink communication technologies(e.g., ProSe and D2D communication technologies, and the like). In thiscase, the communications between the vehicle 100 and the infrastructure120 may be performed using at least one sidelink channel establishedbetween the vehicle 100 and the infrastructure 120.

The V2P communications may include communications between the firstvehicle 100 (e.g., the communication node located in the vehicle 100)and a person 130 (e.g., a communication node carried by the person 130).The driving information of the first vehicle 100 and movementinformation of the person 130 such as velocity, heading, time, position,and the like may be exchanged between the vehicle 100 and the person 130through the V2P communications. The communication node located in thevehicle 100 or the communication node carried by the person 130 maygenerate an alarm indicating a danger by judging a dangerous situationbased on the obtained driving information and movement information. TheV2P communications supported in the cellular communication system 140may be performed based on sidelink communication technologies (e.g.,ProSe and D2D communication technologies, and the like). In this case,the communications between the communication node located in the vehicle100 and the communication node carried by the person 130 may beperformed using at least one sidelink channel established between thecommunication nodes.

The V2N communications may be communications between the first vehicle100 (e.g., the communication node located in the vehicle 100) and aserver connected through the cellular communication system 140. The V2Ncommunications may be performed based on the 4G communication technology(e.g., LTE or LTE-A) or the 5G communication technology (e.g., NR).Also, the V2N communications may be performed based on a Wireless Accessin Vehicular Environments (WAVE) communication technology or a WirelessLocal Area Network (WLAN) communication technology which is defined inInstitute of Electrical and Electronics Engineers (IEEE) 802.11, or aWireless Personal Area Network (WPAN) communication technology definedin IEEE 802.15.

Meanwhile, the cellular communication system 140 supporting the V2Xcommunications may be configured as follows.

FIG. 2 is a conceptual diagram illustrating embodiments of a cellularcommunication system.

As shown in FIG. 2, a cellular communication system may include anaccess network, a core network, and the like. The access network mayinclude a base station 210, a relay 220, User Equipments (UEs) 231through 236, and the like. The UEs 231 through 236 may includecommunication nodes located in the vehicles 100 and 110 of FIG. 1, thecommunication node located in the infrastructure 120 of FIG. 1, thecommunication node carried by the person 130 of FIG. 1, and the like.When the cellular communication system supports the 4G communicationtechnology, the core network may include a serving gateway (S-GW) 250, apacket data network (PDN) gateway (P-GW) 260, a mobility managemententity (MME) 270, and the like.

When the cellular communication system supports the 5G communicationtechnology, the core network may include a user plane function (UPF)250, a session management function (SMF) 260, an access and mobilitymanagement function (AMF) 270, and the like. Alternatively, when thecellular communication system operates in a Non-Stand Alone (NSA) mode,the core network constituted by the S-GW 250, the P-GW 260, and the MME270 may support the 5G communication technology as well as the 4Gcommunication technology, or the core network constituted by the UPF250, the SMF 260, and the AMF 270 may support the 4G communicationtechnology as well as the 5G communication technology.

Also, when the cellular communication system supports a network slicingtechnique, the core network may be divided into a plurality of logicalnetwork slices. For example, a network slice supporting V2Xcommunications (e.g., a V2V network slice, a V2I network slice, a V2Pnetwork slice, a V2N network slice, etc.) may be configured, and the V2Xcommunications may be supported through the V2X network slice configuredin the core network.

The communication nodes (e.g., base station, relay, UE, S-GW, P-GW, MME,UPF, SMF, AMF, etc.) comprising the cellular communication system mayperform communications by using at least one communication technologyamong a code division multiple access (CDMA) technology, a time divisionmultiple access (TDMA) technology, a frequency division multiple access(FDMA) technology, an orthogonal frequency division multiplexing (OFDM)technology, a filtered OFDM technology, an orthogonal frequency divisionmultiple access (OFDMA) technology, a single carrier PUMA (SC-FDMA)technology, a non-orthogonal multiple access (NOMA) technology, ageneralized frequency division multiplexing (GFDM) technology, a filterbank multi-carrier (FBMC) technology, a universal filtered multi-carrier(UFMC) technology, and a space division multiple access (SDMA)technology.

The communication nodes (e.g., base station, relay, UE, S-GW, P-GW, MME,UPF, SMF, AMF, etc.) comprising the cellular communication system may beconfigured as follows.

FIG. 3 is a conceptual diagram illustrating embodiments of acommunication node constituting a cellular communication system.

As shown in FIG. 3, a communication node 300 may comprise at least oneprocessor 310, a memory 320, and a transceiver 330 connected to anetwork for performing communications. Also, the communication node 300may further comprise an input interface device 340, an output interfacedevice 350, a storage device 360, and the like. Each component includedin the communication node 300 may communicate with each other asconnected through a bus 370.

However, each of the components included in the communication node 300may be connected to the processor 310 via a separate interface or aseparate bus rather than the common bus 370. For example, the processor310 may be connected to at least one of the memory 320, the transceiver330, the input interface device 340, the output interface device 350,and the storage device 360 via a dedicated interface.

The processor 310 may execute at least one instruction stored in atleast one of the memory 320 and the storage device 360. The processor310 may refer to a central processing unit (CPU), a graphics processingunit (GPU), or a dedicated processor on which methods in accordance withembodiments of the present disclosure are performed. Each of the memory320 and the storage device 360 may include at least one of a volatilestorage medium and a non-volatile storage medium. For example, thememory 320 may comprise at least one of read-only memory (ROM) andrandom access memory (RAM).

Referring again to FIG. 2, in the communication system, the base station210 may form a macro cell or a small cell, and may be connected to thecore network via an ideal backhaul or a non-ideal backhaul. The basestation 210 may transmit signals received from the core network to theUEs 231 through 236 and the relay 220, and may transmit signals receivedfrom the UEs 231 through 236 and the relay 220 to the core network. TheUEs 231, 232, 234, 235 and 236 may belong to cell coverage of the basestation 210. The UEs 231, 232, 234, 235 and 236 may be connected to thebase station 210 by performing a connection establishment procedure withthe base station 210. The UEs 231, 232, 234, 235 and 236 may communicatewith the base station 210 after being connected to the base station 210.

The relay 220 may be connected to the base station 210 and may relaycommunications between the base station 210 and the UEs 233 and 234.That is, the relay 220 may transmit signals received from the basestation 210 to the UEs 233 and 234, and may transmit signals receivedfrom the UEs 233 and 234 to the base station 210. The UE 234 may belongto both of the cell coverage of the base station 210 and the cellcoverage of the relay 220, and the UE 233 may belong to the cellcoverage of the relay 220. That is, the UE 233 may be located outsidethe cell coverage of the base station 210. The UEs 233 and 234 may beconnected to the relay 220 by performing a connection establishmentprocedure with the relay 220. The UEs 233 and 234 may communicate withthe relay 220 after being connected to the relay 220.

The base station 210 and the relay 220 may support multiple-input,multiple-output (MIMO) technologies (e.g., single user (SU)-MIMO,multi-user (MU)-MIMO, massive MIMO, etc.), coordinated multipoint (CoMP)communication technologies, carrier aggregation (CA) communicationtechnologies, unlicensed band communication technologies (e.g., LicensedAssisted Access (LAA), enhanced LAA (eLAA), etc.), sidelinkcommunication technologies (e.g., ProSe communication technology, D2Dcommunication technology), or the like. The UEs 231, 232, 235 and 236may perform operations corresponding to the base station 210 andoperations supported by the base station 210. The UEs 233 and 234 mayperform operations corresponding to the relays 220 and operationssupported by the relays 220.

Here, the base station 210 may be referred to as a Node B (NB), anevolved Node B (eNB), a base transceiver station (BTS), a radio remotehead (RRH), a transmission reception point (TRP), a radio unit (RU), aroadside unit (RSU), a radio transceiver, an access point, an accessnode, or the like. The relay 220 may be referred to as a small basestation, a relay node, or the like. Each of the UEs 231 through 236 maybe referred to as a terminal, an access terminal, a mobile terminal, astation, a subscriber station, a mobile station, a portable subscriberstation a subscriber station, a node, a device, an on-broad unit (OBU),or the like.

Meanwhile, the communications between the UEs 235 and 236 may beperformed based on the sidelink communication technique. The sidelinkcommunications may be performed based on a one-to-one scheme or aone-to-many scheme. When V2V communications are performed using thesidelink communication technique, the UE 235 may be the communicationnode located in the first vehicle 100 of FIG. 1 and the UE 236 may bethe communication node located in the second vehicle 110 of FIG. 1. WhenV2I communications are performed using the sidelink communicationtechnique, the UE 235 may be the communication node located in firstvehicle 100 of FIG. 1 and the UE 236 may be the communication nodelocated in the infrastructure 120 of FIG. 1. When V2P communications areperformed using the sidelink communication technique, the UE 235 may bethe communication node located in first vehicle 100 of FIG. 1 and the UE236 may be the communication node carried by the person 130 of FIG. 1.

The scenarios to which the sidelink communications are applied may beclassified as shown below in Table 1 according to the positions of theUEs (e.g., the UEs 235 and 236) participating in the sidelinkcommunications. For example, the scenario for the sidelinkcommunications between the UEs 235 and 236 shown in FIG. 2 may be asidelink communication scenario C.

TABLE 1 Sidelink Communication Scenario Position of UE 235 Position ofUE 236 A Out of coverage of base Out of coverage of base station 210station 210 B In coverage of base Out of coverage of base station 210station 210 C In coverage of base In coverage of base station 210station 210 D In coverage of base In coverage of other station 210 basestation

Meanwhile, a user plane protocol stack of the UEs (e.g., the UEs 235 and236) performing sidelink communications may be configured as follows.

FIG. 4 is a block diagram illustrating embodiments of a user planeprotocol stack of an UE performing sidelink communication.

As shown in FIG. 4, a left UE may be the UE 235 shown in FIG. 2 and aright UE may be the UE 236 shown in FIG. 2. The scenario for thesidelink communications between the UEs 235 and 236 may be one of thesidelink communication scenarios A through D of Table 1. The user planeprotocol stack of each of the UEs 235 and 236 may comprise a physical(PHY) layer, a medium access control (MAC) layer, a radio link control(RLC) layer, and a packet data convergence protocol (PDCP) layer.

The sidelink communications between the UEs 235 and 236 may be performedusing a PC5 interface (e.g., PC5-U interface). A layer-2 identifier (ID)(e.g., a source layer-2 ID, a destination layer-2 ID) may be used forthe sidelink communications and the layer 2-ID may be an ID configuredfor the V2X communications (e.g., V2X service). Also, in the sidelinkcommunications, a hybrid automatic repeat request (HARQ) feedbackoperation may be supported, and an RLC acknowledged mode (RLC AM) or anRLC unacknowledged mode (RLC UM) may be supported.

Meanwhile, a control plane protocol stack of the UEs (e.g., the UEs 235and 236) performing sidelink communications may be configured asfollows.

FIG. 5 is a block diagram illustrating a first embodiment of a controlplane protocol stack of an UE performing sidelink communication, andFIG. 6 is a block diagram illustrating a second embodiment of a controlplane protocol stack of an UE performing sidelink communication.

As shown in FIGS. 5 and 6, a left UE may be the UE 235 shown in FIG. 2and a right UE may be the UE 236 shown in FIG. 2. The scenario for thesidelink communications between the UEs 235 and 236 may be one of thesidelink communication scenarios A through D of Table 1. The controlplane protocol stack illustrated in FIG. 5 may be a control planeprotocol stack for transmission and reception of broadcast information(e.g., Physical Sidelink Broadcast Channel (PSBCH)).

The control plane protocol stack shown in FIG. 5 may include a PHYlayer, a MAC layer, an RLC layer, and a radio resource control (RRC)layer. The sidelink communications between the UEs 235 and 236 may beperformed using a PC5 interface (e.g., PC5-C interface). The controlplane protocol stack shown in FIG. 6 may be a control plane protocolstack for one-to-one sidelink communication. The control plane protocolstack shown in FIG. 6 may include a PHY layer, a MAC layer, an RLClayer, a PDCP layer, and a PC5 signaling protocol layer.

Meanwhile, channels used in the sidelink communications between the UEs235 and 236 may include a Physical Sidelink Shared Channel (PSSCH), aPhysical Sidelink Control Channel (PSCCH), a Physical Sidelink DiscoveryChannel (PSDCH), and a Physical Sidelink Broadcast Channel (PSBCH). ThePSSCH may be used for transmitting and receiving sidelink data and maybe configured in the UE (e.g., UE 235 or 236) by a higher layersignaling. The PSCCH may be used for transmitting and receiving sidelinkcontrol information (SCI) and may also be configured in the UE (e.g., UE235 or 236) by a higher layer signaling.

The PSDCH may be used for a discovery procedure. For example, adiscovery signal may be transmitted over the PSDCH. The PSBCH may beused for transmitting and receiving broadcast information (e.g., systeminformation). Also, a demodulation reference signal (DM-RS), asynchronization signal, or the like may be used in the sidelinkcommunications between the UEs 235 and 236.

Meanwhile, a sidelink transmission mode (TM) may be classified intosidelink TMs 1 to 4 as shown below in Table 2.

TABLE 2 Sidelink TM Description 1 Transmission using resources scheduledby base station 2 UE autonomous transmission without scheduling of basestation 3 Transmission using resources scheduled by base station in V2Xcommunications 4 UE autonomous transmission without scheduling of basestation in V2X communications

When the sidelink TM 3 or 4 is supported, each of the UEs 235 and 236may perform sidelink communications using a resource pool configured bythe base station 210. The resource pool may be configured for each ofthe sidelink control information and the sidelink data.

The resource pool for the sidelink control information may be configuredbased on an RRC signaling procedure (e.g., a dedicated RRC signalingprocedure, a broadcast RRC signaling procedure). The resource pool usedfor reception of the sidelink control information may be configured by abroadcast RRC signaling procedure. When the sidelink TM 3 is supported,the resource pool used for transmission of the sidelink controlinformation may be configured by a dedicated RRC signaling procedure. Inthis case, the sidelink control information may be transmitted throughresources scheduled by the base station 210 within the resource poolconfigured by the dedicated RRC signaling procedure. When the sidelinkTM 4 is supported, the resource pool used for transmission of thesidelink control information may be configured by a dedicated RRCsignaling procedure or a broadcast RRC signaling procedure. In thiscase, the sidelink control information may be transmitted throughresources selected autonomously by the UE (e.g., UE 235 or 236) withinthe resource pool configured by the dedicated RRC signaling procedure orthe broadcast RRC signaling procedure.

When the sidelink TM 3 is supported, the resource pool for transmittingand receiving sidelink data may not be configured. In this case, thesidelink data may be transmitted and received through resourcesscheduled by the base station 210. When the sidelink TM 4 is supported,the resource pool for transmitting and receiving sidelink data may beconfigured by a dedicated RRC signaling procedure or a broadcast RRCsignaling procedure. In this case, the sidelink data may be transmittedand received through resources selected autonomously by the UE (e.g., UE235 or 236) within the resource pool configured by the dedicated RRCsignaling procedure or the broadcast RRC signaling procedure.

Next, methods for transmitting and receiving sidelink controlinformation (SCI) including configuration information for transmissionand reception in the communication system (e.g., cellular communicationsystem) supporting the V2X communication as described above will bedescribed. Even when a method (e.g., transmission or reception of asignal) to be performed at a first communication node amongcommunication nodes is described, a corresponding second communicationnode may perform a method (e.g., reception or transmission of thesignal) corresponding to the method performed at the first communicationnode. That is, when an operation of a first vehicle is described, acorresponding second vehicle may perform an operation corresponding tothe operation of the first vehicle. Conversely, when an operation of thesecond vehicle is described, the corresponding first vehicle may performan operation corresponding to the operation of the second vehicle. Inthe embodiments described below, the operation of the vehicle may be theoperation of the communication node located in the vehicle.

A terminal located in a vehicle may operate as a relay. In this case,the terminal may perform V2X communication with a base station, and mayperform V2X sidelink communication with other terminals. For example,the terminal operating as a relay may perform communication as follows.

FIG. 7 is a conceptual diagram illustrating a first embodiment of a V2Xcommunication system.

As shown in FIG. 7, a V2X communication system may comprise a basestation 700, a first terminal 710, and a second terminal 720. The basestation 700 may belong to the cellular communication system 140 shown inFIG. 1, the first terminal 710 may be located in the first vehicle 100shown in FIG. 1, and the second terminal 720 may be located in thesecond vehicle 110 shown in FIG. 1. Each of the first terminal 710 andthe second terminal 720 may support TM 3 or TM 4 defined in Table 2.Also, each of the first terminal 710 and the second terminal 720 mayinclude the protocol stacks shown in FIGS. 4 to 6. Each of the basestation 700, the first terminal 710 and the second terminal 720 may beconfigured to be the same as or similar to the communication node 300shown in FIG. 3.

The first terminal 710 may be located within cell coverage of the basestation 700 and may perform V2X communication with the base station 700.Also, the first terminal 710 may perform V2X sidelink communication withthe second terminal 720. When data to be transmitted to the secondterminal 720 is generated, the first terminal 710 may transmit an SCIincluding resource allocation information to the second terminal 720 andthen use a resource scheduled by the SCI to transmit the data to thesecond terminal 720. The second terminal 720 may receive the SCI fromthe first terminal 710, and may receive the data from the first terminal710 by monitoring the resource indicated by the received SCI. The SCIand the data may be transmitted in the same subframe. Alternatively,when the SCI is transmitted in a subframe #n, the data may betransmitted in a subframe #(n+k). Here, n may be an integer greater thanor equal to 0, and k may be an integer greater than or equal to 1.

When data to be transmitted from the base station 700 to the firstterminal 710 is generated, the base station 700 may transmit downlinkcontrol information (DCI) including resource allocation information tothe first terminal 710, and may transmit the data to the first terminal710 using a resource scheduled by the DCI. The first terminal 710 mayreceive the DCI from the base station 700 and receive the data from thebase station 700 by monitoring the resource indicated by the receivedDCI. Also, the scheduling information included in the DCI of the basestation 700 may indicate that the data is to be transmitted from thebase station 700 to the first terminal 710 according to a predeterminedperiodicity. For example, the DCI of the base station 700 may be usedfor semi-persistent scheduling (SPS).

The second terminal 720 may be located outside the cell coverage of thebase station 700 and may not receive the DCI of the base station 700.Therefore, the second terminal 720 may not know the resource used forcommunication between the base station 700 and the first terminal 710.In this situation, when data to be transmitted from the second terminal720 to the first terminal 710 is generated, the second terminal 720 maytransmit an SCI and the data to the first terminal 710 based on the V2Xsidelink communication scheme. A radio resource occupied by a V2Xsidelink signal transmitted from the second terminal 720 to the firstterminal 710 may be overlapped with a radio resource occupied by adownlink signal transmitted from the base station 700 to the firstterminal 710. Therefore, the first terminal 710 may not receive both theV2X sidelink signal of the second terminal 720 and the downlink signalof the base station 700.

Meanwhile, in a platooning scenario, terminals located in vehicles mayperform V2X sidelink communications. For example, one or more terminalsamong the terminals may operate as a coordinator for the platooning, andthe coordinator may perform V2X sidelink communications with otherterminals. In the platooning scenario, the terminals may communicate asfollows.

FIG. 8 is a conceptual diagram illustrating a second embodiment of a V2Xcommunication system.

As shown in FIG. 8, a V2X communication system may comprise a basestation 700, a first terminal 710, a second terminal 720, and a thirdterminal 730. The first terminal 710, the second terminal 720, and thethird terminal 730 may be located in different vehicles participating inthe platooning. Each of the first terminal 710, the second terminal 720,and the third terminal 730 may support TM 3 or TM 4 defined in Table 2.Also, each of the first terminal 710, the second terminal 720, and thethird terminal 730 may include the protocol stacks shown in FIGS. 4 to6. Each of the base station 700, the first terminal 710, the secondterminal 720, and the third terminal 730 may be configured to be thesame as or similar to the communication node 300 shown in FIG. 3.

The first terminal 710 may operate as a coordinator for the platooning,and may perform V2X sidelink communication with the second terminal 720and the third terminal 730, respectively. When data to be transmittedfrom the first terminal 710 to the second terminal 720 is generated, thefirst terminal 710 may transmit an SCI including resource allocationinformation to the second terminal 720, and transmit the data to thesecond terminal 720 by using a resource scheduled by the SCI. The secondterminal 720 may receive the SCI from the first terminal 710, andreceive the data from the first terminal 710 by monitoring the resourceindicated by the received SCI. The SCI and the data may be transmittedin the same subframe. Alternatively, the subframe in which the SCI istransmitted may be different from the subframe in which the data istransmitted.

When data to be transmitted from the third terminal 730 to the firstterminal 710 is generated, the third terminal 730 may transmit an SCIincluding resource allocation information to the first terminal 710, andtransmit the data to the first terminal 710 by using a resourcescheduled by the SCI. The first terminal 710 may receive the SCI fromthe third terminal 730, and receive the data from the third terminal 730by monitoring the resource indicated by the received SCI. The schedulinginformation included in the SCI of the third terminal 730 may indicatethat the data is to be transmitted from the third terminal 730 to thefirst terminal 710 according to a predetermined periodicity. Forexample, the SCI of the third terminal 730 may be used for SPS.

The second terminal 720 may be located outside the coverage of the thirdterminal 730 and may not receive the SCI of the third terminal 730.Therefore, the second terminal 720 may not know the resource used forcommunication between the third terminal 730 and the first terminal 710.In this situation, when data to be transmitted from the second terminal720 to the first terminal 710 is generated, the second terminal 720 maytransmit an SCI and the data to the first terminal 710 based on the V2Xsidelink communication scheme. A radio resource occupied by a V2Xsidelink signal transmitted from the second terminal 720 to the firstterminal 710 may be overlapped with a radio resource occupied by a V2Xsidelink signal transmitted from the third terminal 730 to the firstterminal 710. Therefore, the first terminal 710 may not receive both theV2X sidelink signal of the second terminal 720 and the V2X sidelinksignal of the third terminal 730.

In order to solve the problems of the examples shown in FIGS. 7 and 8,the first terminal 710 may generate an SCI including the resourceallocation information included in the DCI received from the basestation 700 or the SCI received from the third terminal 730, andtransmit the generated SCI to the second terminal 720. A transmissionprocedure of the SCI including the resource allocation informationincluded in the DCI or SCI received from another communication node(e.g., the base station 700 or the third terminal 730) may be triggeredby the base station 700. A method for triggering the SCI transmissionprocedure may be as follows.

FIG. 9 is a sequence chart illustrating a first embodiment of a methodfor triggering an SCI transmission/reception procedure in a V2Xcommunication system.

As shown in FIG. 9, a V2X communication system may comprise a basestation 700, a first terminal 710, a second terminal 720, and a thirdterminal 730. The base station 700, the first terminal 710, the secondterminal 720, and the third terminal 730 may be the base station 700,the first terminal 710, the second terminal 720, and the third terminal730 which are shown in FIG. 8. Each of the first terminal 710, thesecond terminal 720, and the third terminal 730 may support TM 3 or TM 4defined in Table 2. Also, each of the first terminal 710, the secondterminal 720, and the third terminal 730 may include the protocol stacksshown in FIGS. 4 to 6. Each of the base station 700, the first terminal710, the second terminal 720, and the third terminal 730 may beconfigured to be the same as or similar to the communication node 300shown in FIG. 3.

The first terminal 710 operating as a relay or a coordinator forplatooning may generate a first message (e.g., RRC message) includinginformation indicating that the first terminal 710 operates as a relayor a coordinator for platooning. Alternatively, the first message mayinclude information requesting permission of transmission of an SCIincluding reception configuration information. The first terminal 710may transmit the first message to the base station 700 (S901). The firstmessage may be transmitted according to a connection establishmentprocedure between the first terminal 710 and the base station 700. Inthis case, the operation state of the first terminal 710 may be anRRC_Idle state. Alternatively, the first message may be transmitted bythe first terminal 710 operating in an RRC_connected state or anRRC_inactive state. Here, the first message may be sidelink UEinformation.

The base station 700 may receive the first message from the firstterminal 710 and determine that the first terminal 710 operates as arelay or a coordinator for platooning based on the information includedin the received first message. Alternatively, the base station 700 maydetermine that the transmission of the SCI including the receptionconfiguration information is requested. In this case, in order to solvethe problems of the examples shown in FIG. 7 or 8, the base station 700may transmit to the first terminal 710 a second message includinginformation instructing to transmit the SCI including the receptionconfiguration information (S902). The first terminal 710 may receive thesecond message from the base station, and determine that thetransmission of the SCI including the reception configurationinformation is permitted based on the information included in thereceived message. The second message may be an RRC message, a messageincluding a MAC control element (CE), or a message including a DCI.

The reception configuration information may be configuration informationused by the first terminal 710 to receive data from anothercommunication node (e.g., the base station 700, the second terminal 720,or the third terminal 730). For example, the reception configurationinformation may be the resource allocation information included in theDCI received by the first terminal 710 from the base station 700.Alternatively, the reception configuration information may be theresource allocation information included in the SCI received by thefirst terminal 710 from the second terminal 720 or the third terminal730. The transmission configuration information may be configurationinformation used by the first terminal 710 to transmit data to anothercommunication node (e.g., the first terminal 720 or the third terminal730).

Also, the first terminal 710 may generate a third message includinginformation indicating that the SCI including the receptionconfiguration information is to be transmitted, and transmit thegenerated third message to other terminals (e.g., the second terminal720 and the third terminal 730) (S903). The second terminal 720 and thethird terminal 730 may receive the third message from the first terminal710, and based on the information included in the received thirdmessage, the second terminal 720 may determine that the SCI includingthe reception configuration information is to be transmitted based onthe information included in the received third message. Here, the thirdmessage may be an RRC message, a message including a MAC CE, or asignaling message according to the PC5 signaling protocol.

Meanwhile, in the platooning scenario, a platooning identifier (PID) forthe first terminal 710 operating as a coordinator may be configured. ThePID may be configured according to the connection establishmentprocedure between the first terminal 710 and the base station 700. Forexample, the base station 700 may set the PID for the first terminal 710and transmit an RRC message including the set PID to the first terminal710. The first terminal 710 may obtain the PID by receiving the RRCmessage from the base station 700. The first terminal 710 may notify thePID to other terminals participating in the platooning (e.g., the secondterminal 720 and the third terminal 730). For example, the PID may becommonly used in the terminals (e.g., the first terminal 710, the secondterminal 720, and the third terminal 730) participating in theplatooning. The PID may be used as an area identifier (AID).

In the embodiment shown in FIG. 10, the SCI may further include a PID,and the terminal receiving the SCI may compare its PID with the PIDincluded in the SCI. When the PID of the terminal and the PID includedin the SCI are the same, the terminal may perform V2X sidelinkcommunication using the information included in the SCI. On the otherhand, when the PID of the terminal and the PID included in the SCI aredifferent from each other, the terminal may discard the SCI. Also, inthe platooning scenario, a sequence of a reference signal or a discoverysignal may be generated based on the PID.

Meanwhile, when the transmission of the SCI including the receptionconfiguration information is permitted, the first terminal 710 maytransmit the SCI including the reception configuration information.Alternatively, regardless of whether the transmission of the SCIincluding the reception configuration information is permitted or not,the first terminal 710 may transmit the SCI including the receptionconfiguration information. In this case, the triggering method shown inFIG. 9 may not be performed.

A format of the SCI may be configured according to whether or not thereception configuration information is included. For example, the SCIformat may be configured based on Table 3 below.

TABLE 3 Reception Transmission configuration configuration Format indexinformation information SCI format 1 00 Not included Included SCI format1A 01 Included Not included SCI format 1B 10 Included Included

A format index for each of SCI format 1, SCI format 1A, and SCI format1B may be set. For example, the format index of the SCI format 1 may beset to ‘00’, the format index of the SCI format 1A may be set to ‘01’,and the format index of the SCI format 1B may be set to ‘10’. In thiscase, the SCI having the format 1 may include the format index set to‘00’, the SCI having the format 1A may include the format index set to‘01’ and the SCI having the format 1B may include the format index setto ‘10’.

In the V2X communication system, a transmission and reception method ofthe SCI including the reception configuration information may be asfollows.

FIG. 10 is a sequence chart illustrating a first embodiment of an SCItransmission and reception method in a V2X communication system.

As shown in FIG. 10, a V2X communication system may comprise a basestation 700, a first terminal 710, a second terminal 720, and a thirdterminal 730. The base station 700, the first terminal 710, the secondterminal 720, and the third terminal 730 may be the base station 700,the first terminal 710, the second terminal 720, and the third terminal730 which are shown in FIG. 8. Each of the first terminal 710, thesecond terminal 720, and the third terminal 730 may support TM 3 or TM 4defined in Table 2. Also, each of the first terminal 710, the secondterminal 720, and the third terminal 730 may include the protocol stacksshown in FIGS. 4 to 6. Each of the base station 700, the first terminal710, the second terminal 720, and the third terminal 730 may beconfigured to be the same as or similar to the communication node 300shown in FIG. 3.

When data to be transmitted from the first terminal 710 to the secondterminal 720 is generated, the first terminal 710 may generate an SCIformat 1 (e.g., the SCI format 1 defined in Table 3) includingtransmission configuration information for the data of the secondterminal 720 (S1001). The SCI format 1 (e.g., transmission configurationinformation) may include one or more parameters defined in Table 4below.

TABLE 4 Parameters SCI format 1 Format index Priority Resourcereservation Frequency resource location Time interval Modulation andcoding scheme (MCS) Retransmission index Valid period

The ‘format index’ of Table 4 may be set to ‘00’. The ‘frequencyresource location’ of Table 4 may indicate the location of the frequencyresource for initial transmission and retransmission. The ‘timeinterval’ of Table 4 may indicate a time interval between the initialtransmission and the retransmission. The ‘valid period’ of Table 4 mayindicate a period during which data transmission is restricted. The‘valid period’ may start at a transmission time of the SCI format 1.

The first terminal 710 may transmit the SCI format 1 and the data to thesecond terminal 720 (S1002). A subframe in which the SCI format 1 istransmitted may be the same as a subframe in which data scheduled by theSCI format 1 is transmitted. Alternatively, a subframe in which the SCIformat 1 is transmitted may be different from a subframe in which datascheduled by the SCI format 1 is transmitted. The second terminal 720may receive the SCI format 1 from the first terminal 710, and identifythe format index included in the received SCI format 1. When the formatindex is set to ‘00’, the second terminal 720 may determine that the SCIformat 1 includes the transmission configuration information, and mayreceive the data based on the transmission configuration informationincluded in the SCI format 1.

In addition, when the SCI format 1 includes the valid period, the secondterminal 720 may not transmit data to the first terminal 710 during thevalid period indicated by the SCI format 1. That is, when data to betransmitted from the second terminal 720 to the first terminal 710 isgenerated, the second terminal 720 may transmit the data to the firstterminal 710 after the valid period indicated by the SCI format 1expires.

Meanwhile, when data to be transmitted from a communication node (e.g.,the base station 700 or the third terminal 730) to the first terminal710 is generated, the communication node 700 or 730 may generate an SCIformat 1 including transmission configuration information for the dataof the first terminal 710 (S1003). The SCI format 1 (e.g., transmissionconfiguration information) may include one or more parameters defined inTable 4.

The communication node 700 or 730 may transmit the SCI format 1 and thedata to the first terminal 710 (S1004). A subframe in which the SCIformat 1 is transmitted may be the same as a subframe in which datascheduled by the SCI format 1 is transmitted. Alternatively, a subframein which the SCI format 1 is transmitted may be different from asubframe in which data scheduled by the SCI format 1 is transmitted. Thefirst terminal 710 may receive the SCI format 1 from the communicationnode 700 or 730, and identify the format index included in the receivedSCI format 1. When the format index is set to ‘00’, the first terminal710 may determine that the SCI format 1 includes the transmissionconfiguration information, and may receive the data based on thetransmission configuration information included in the SCI format 1.

In addition, when the SCI format 1 includes the valid period, the firstterminal 710 may not transmit data to the communication node 700 or 730during the valid period indicated by the SCI format 1. That is, whendata to be transmitted from the first terminal 710 to the communicationnode 700 or 730 is generated, the first terminal 710 may transmit thedata to the communication node 700 or 730 after the valid periodindicated by the SCI format 1 expires.

Also, the first terminal 710 may generate reception configurationinformation based on resource allocation information of the data amongthe information included in the SCI format 1 received from thecommunication node 700 or 730. For example, the first terminal 710 maygenerate information (e.g., transmission cycle, time resource, frequencyresource) indicating a time-frequency resource used for the datatransmitted from the communication node 700 or 730 to the first terminal710 based on the information (e.g., ‘resource reservation’, ‘frequencyresource location’, and ‘time interval’) included in the SCI format 1,and generate the reception configuration information including theinformation indicating the time-frequency resource.

The first terminal 710 may generate an SCI format 1A including thereception configuration information (S1005). When there is no data to betransmitted from the first terminal 710 to the second terminal 720, theSCI format 1A may be generated instead of the SCI format 1B. The SCIformat 1A may include one or more parameters defined in Table 5 below.

TABLE 5 Parameters SCI format 1A Format index Transmission cycle Timeresource Frequency resource Valid period

The SCI format 1A may include a resource reservation field, a frequencyresource location field, and a time interval field. In this case, thetransmission cycle defined in Table 5 may be indicated by the resourcereservation field, the time resource defined in Table 5 may be indicatedby the time interval field, and the frequency resource defined in Table5 may be indicated by the frequency resource location field.

The first terminal 710 may transmit the SCI format 1A to the secondterminal 720 (S1006). That is, the SCI format 1A may be transmittedwithout data. The second terminal 720 may receive the SCI format 1A fromthe first terminal 710, and identify the format index included in thereceived SCI format 1A. When the format index is set to ‘01’, the secondterminal 720 may determine that the SCI format 1A includes the receptionconfiguration information, and may identify the reception configurationinformation included in the SCI format 1A.

When data to be transmitted from the second terminal 720 to the firstterminal 710 is generated, the second terminal 720 may transmit the datato the first terminal 710 by using a resource not overlapped with thetime-frequency resource indicated by the SCI format 1A. For example,when there are insufficient available resources in a frequency band(e.g., a channel) to which a frequency resource indicated by the SCIformat 1A belongs, the second terminal 720 may transmit the data to thefirst terminal 710 by using a frequency band different from thefrequency band indicated by the SCI format 1A. Also, when the SCI format1A includes the valid period, the second terminal 720 may not transmitthe data to the first terminal 710 during the valid period indicated bythe SCI format 1A. That is, when data to be transmitted from the secondterminal 720 to the first terminal 710 is generated, the second terminal720 may transmit the data to the first terminal 710 after the validperiod indicated by the SCI format 1A expires.

Meanwhile, when data to be transmitted from the communication node 700or 730 to the first terminal 710 is generated, the communication node700 or 730 may generate an SCI format 1 including transmissionconfiguration information for the data of the first terminal 710(S1007). The SCI format 1 (e.g., transmission configuration information)may include one or more parameters defined in Table 4.

The communication node 700 or 730 may transmit the SCI format 1 and thedata to the first terminal 710 (S1008). A subframe in which the SCIformat 1 is transmitted may be the same as a subframe in which datascheduled by the SCI format 1 is transmitted. Alternatively, a subframein which the SCI format 1 is transmitted may be different from asubframe in which data scheduled by the SCI format 1 is transmitted. Thefirst terminal 710 may receive the SCI format 1 from the communicationnode 700 or 730, and identify the format index included in the receivedSCI format 1. When the format index is set to ‘00’, the first terminal710 may determine that the SCI format 1 includes the transmissionconfiguration information, and may receive the data based on thetransmission configuration information included in the SCI format 1.

In addition, when the SCI format 1 includes the valid period, the firstterminal 710 may not transmit data to the communication node 700 or 730during the valid period indicated by the SCI format 1. That is, whendata to be transmitted from the first terminal 710 to the communicationnode 700 or 730 is generated, the first terminal 710 may transmit thedata to the communication node 700 or 730 after the valid periodindicated by the SCI format 1 expires.

When the SCI format 1 is received from the communication node 700 or 730and data to be transmitted from the first terminal 710 to the secondterminal 720 is generated, the first terminal may generate an SCI format1B including transmission configuration information and receptionconfiguration information (S1009). The transmission configurationinformation may be configuration information used by the first terminal710 to transmit the data to the second terminal 720. The transmissionconfiguration information may include one or more parameters defined inTable 4.

The first terminal 710 may generate reception configuration informationbased on resource allocation information of the data among theinformation included in the SCI format 1 received from the communicationnode 700 or 730. For example, the first terminal 710 may generateinformation (e.g., transmission cycle, time resource, frequencyresource) indicating a time-frequency resource used for the datatransmitted from the communication node 700 or 730 to the first terminal710 based on the information (e.g., ‘resource reservation’, ‘frequencyresource location’, and ‘time interval’) included in the SCI format 1,and generate the reception configuration information including theinformation indicating the time-frequency resource.

The SCI format 1B including the transmission configuration informationand the reception configuration information may include one or moreparameters defined in Table 6 below.

TABLE 6 Parameters SCI format 1B Transmission Format index configurationPriority information Resource reservation Frequency resource locationTime interval Modulation and coding scheme (MCS) Retransmission indexReception Transmission cycle configuration Time resource informationFrequency resource Valid period

The SCI format 1B may include fields used for indicating transmissionconfiguration information and fields used for indicating receptionconfiguration information (hereinafter referred to as ‘receptionconfiguration fields’). The reception configuration fields may include aresource reservation field, a frequency resource location field, and atime interval field. The resource reservation field included in thereception configuration fields may be used to indicate the transmissioncycle defined in Table 6. The frequency resource location field includedin the reception configuration fields may be used to indicate thefrequency resource defined in Table 6. The time interval field includedin the reception configuration fields may be used to indicate the timeresource defined in Table 6.

Alternatively, the resource reservation field may be omitted in thereception configuration fields. In that case, the information indicatingthe transmission cycle as the reception configuration information may beincluded in the resource reservation field of the transmissionconfiguration fields (e.g., transmission configuration information)belonging to the SCI format 1B. In that case, the resource reservationfield included in the transmission configuration fields may indicate thetransmission cycle belonging to the transmission configurationinformation as well as the transmission cycle belonging to the receptionconfiguration information. Alternatively, the time interval field may beomitted in the reception configuration fields. In that case, theinformation indicating the time resource as the reception configurationinformation may be included in the time interval field of thetransmission configuration fields belonging to the SCI format 1B. Inthat case, the time interval field included in the transmissionconfiguration fields may indicate the time resource belonging to thetransmission configuration information as well as the time resourcebelonging to the reception configuration information.

The ‘transmission cycle’ included in the SCI format 1B may explicitlyindicate a transmission cycle of data transmitted from the communicationnode 700 or 730 to the first terminal 710. Alternatively, the‘transmission cycle’ included in the SCI format 1B may indicate anoffset between a transmission cycle of data transmitted from the firstterminal 710 to the second terminal 720 and a transmission cycle of datatransmitted from the communication node 700 or 730 to the first terminal710.

The ‘time resource’ included in the SCI format 1B may explicitlyindicate a time resource for data transmitted from the communicationnode 700 or 730 to the first terminal 710. Alternatively, the ‘timeresource’ included in the SCI format 1B may indicate an offset between atime resource (e.g., a start time point or an end time point of the timeresource) for data transmitted from the first terminal 710 to the secondterminal 720 and a time resource (e.g., a start time point or an endtime point of the time resource) for data transmitted from thecommunication node 700 or 730 to the first terminal 710. In this case,the SCI format 1B may further include information indicating a durationof the time resource for the data transmitted from the communicationnode 700 or 730 to the first terminal 710. Therefore, the time resourcefor the data transmitted from the communication node 700 or 730 to thefirst terminal 710 may be identified based on the offset and theduration for the time resource included in the SCI format 1B.

The ‘frequency resource’ included in the SCI format 1B may explicitlyindicate a frequency resource for data transmitted from thecommunication node 700 or 730 to the first terminal 710. Alternatively,the ‘frequency resource’ included in the SCI format 1B may indicate anoffset between a frequency resource (e.g., a start position or an endposition of the frequency resource) for data transmitted from the firstterminal 710 to the second terminal 720 and a frequency resource (e.g.,a start position or an end position of the frequency resource) for datatransmitted from the communication node 700 or 730 to the first terminal710. In this case, the SCI format 1B may further include informationindicating the size of the frequency resource (e.g., bandwidth) for thedata transmitted from the communication node 700 or 730 to the firstterminal 710. Therefore, the frequency resource for the data transmittedfrom the communication node 700 or 730 to the first terminal 710 may beidentified based on the offset and the bandwidth for the frequencyresource included in the SCI format 1B.

The first terminal 710 may transmit the SCI format 1B and the data tothe second terminal 720 (S1010). A subframe in which the SCI format 1Bis transmitted may be the same as a subframe in which data scheduled bythe SCI format 1B is transmitted. Alternatively, a subframe in which theSCI format 1B is transmitted may be different from a subframe in whichdata scheduled by the SCI format 1B is transmitted. The second terminal720 may receive the SCI format 1B from the first terminal 710, andidentify the format index included in the received SCI format 1B. Whenthe format index is set to ‘10’, the second terminal 720 may determinethat the SCI format 1B includes the transmission configurationinformation and the reception configuration information based on theformat index.

The second terminal 720 may receive the data based on the transmissionconfiguration information included in the SCI format 1B. Also, thesecond terminal 720 may identify the reception configuration informationincluded in the SCI format 1B. When data to be transmitted from thesecond terminal 720 to the first terminal 710 is generated, the secondterminal 720 may transmit the data to the first terminal 710 by using aresource not overlapped with the time-frequency resource indicated bythe reception configuration information included in the SCI format 1B.For example, when there are insufficient available resources in afrequency band (e.g., a channel) to which a frequency resource indicatedby the reception configuration information included in the SCI format 1Bbelongs, the second terminal 720 may transmit the data to the firstterminal 710 by using a frequency band different from the frequency bandindicated by the SCI format 1B.

Also, when the SCI format 1B includes the valid period, the secondterminal 720 may not transmit the data to the first terminal 710 duringthe valid period indicated by the SCI format 1B. That is, when data tobe transmitted from the second terminal 720 to the first terminal 710 isgenerated, the second terminal 720 may transmit the data to the firstterminal 710 after the valid period indicated by the SCI format 1Bexpires.

While the embodiments of the present disclosure and their advantageshave been described in detail, it should be understood that variouschanges, substitutions and alterations may be made herein withoutdeparting from the scope of the present disclosure.

What is claimed is:
 1. An operation method of a first communication nodelocated in a vehicle supporting a vehicle-to-everything (V2X)communication system, the operation method comprising: receiving, by thefirst communication node, control information including resourceallocation information from a second communication node; receiving, bythe first communication node, data from the second communication nodethrough a radio resource indicated by the resource allocationinformation included in the control information; generating, by thefirst communication node, sidelink control information (SCI) includingreception configuration information indicating the radio resource usedfor transmission of the data by the second communication node based onthe resource allocation information; and transmitting, by the firstcommunication node, the SCI to a third communication node.
 2. Theoperation method according to claim 1, wherein the SCI further includesa format index indicating whether the SCI includes the receptionconfiguration information.
 3. The operation method according to claim 1,wherein the reception configuration information includes at least one ofinformation indicating a transmission cycle of the data transmitted bythe second communication node, information indicating a time resourcethrough which the data is transmitted by the second communication node,and information indicating a frequency resource through which the datais transmitted by the second communication node.
 4. The operation methodaccording to claim 3, wherein the reception configuration informationfurther includes information indicating a valid period during which datatransmission from the third communication node to the firstcommunication node is restricted.
 5. The operation method according toclaim 1, further comprising: transmitting, by the first communicationnode, a first message to the second communication node, the firstmessage including information indicating that the first communicationnode operates as a relay or a coordinator; and receiving, by the firstcommunication node, a second message from the second communication node,the second message including information instructing to transmit the SCIincluding the reception configuration information, wherein the firstcommunication node transmits the SCI in response to receiving the secondmessage.
 6. The operation method according to claim 5, wherein the firstmessage and the second message are transmitted and received according toa connection establishment procedure between the first communicationnode and the second communication node.
 7. The operation methodaccording to claim 1, further comprising transmitting, by the firstcommunication node, a third message to the third communication node, thethird message including information indicating that the SCI includingthe reception configuration information is to be transmitted by thefirst communication node, wherein the first communication node transmitsthe SCI after the third message is transmitted.
 8. The operation methodaccording to claim 7, wherein the third message is a radio resourcecontrol (RRC) message, a message including a medium access control (MAC)control element (CE), or a message according to a PC5 signalingprotocol.
 9. An operation method of a first communication node locatedin a vehicle supporting a vehicle-to-everything (V2X) communicationsystem, the operation method comprising: receiving, by the firstcommunication node, control information including resource allocationinformation from a second communication node; receiving, by the firstcommunication node, first data from the second communication nodethrough a radio resource indicated by the resource allocationinformation included in the control information; generating, by thefirst communication node, reception configuration information indicatingthe radio resource used for transmission of the first data based on theresource allocation information; generating, by the first communicationnode, transmission configuration information for second data to betransmitted to a third communication node; and transmitting, by thefirst communication node, sidelink control information (SCI) includingthe reception configuration information and the transmissionconfiguration information to the third communication node.
 10. Theoperation method according to claim 9, wherein the SCI further includesa format index indicating whether the SCI includes the receptionconfiguration information and the transmission configurationinformation.
 11. The operation method according to claim 9, wherein thereception configuration information includes at least one of informationindicating a transmission cycle of the first data, informationindicating a time resource through which the first data is transmitted,and information indicating a frequency resource through which the firstdata is transmitted.
 12. The operation method according to claim 11,wherein the reception configuration information further includesinformation indicating a valid period during which data transmissionfrom the third communication node to the first communication node isrestricted.
 13. The operation method according to claim 9, wherein thetransmission configuration information includes scheduling informationused for transmission and reception of the second data.
 14. Theoperation method according to claim 9, further comprising: transmitting,by the first communication node, to the second communication node afirst message including information requesting permission oftransmission of the SCI including the reception configurationinformation; and receiving, by the first communication node, from thesecond communication node a second message including informationinstructing the first communication node to transmit the SCI includingthe reception configuration information, wherein the first communicationnode transmits the SCI in response to receiving the second message. 15.The operation method according to claim 9, further comprisingtransmitting, by the first communication node, a third message to thethird communication node, the third message including informationindicating that the SCI including the reception configurationinformation is to be transmitted by the first communication node,wherein the first communication node transmits the SCI after the thirdmessage is transmitted.
 16. The operation method according to claim 15,wherein the third message is a radio resource control (RRC) message, amessage including a medium access control (MAC) control element (CE), ora message according to a PC5 signaling protocol.
 17. An operation methodof a first communication node located in a vehicle supporting avehicle-to-everything (V2X) communication system, the operation methodcomprising: receiving, by the first communication node, sidelink controlinformation (SCI) from a second communication node; identifying, by thefirst communication node, a format index included in the SCI; andobtaining, by the first communication node, reception configurationinformation included in the SCI when the format index indicates that theSCI includes the reception configuration information, wherein thereception configuration information includes information indicating aradio resource allocated for first data transmitted from a thirdcommunication node to the second communication node.
 18. The operationmethod according to claim 17, further comprising, when the SCI includesscheduling information for second data to be transmitted from the secondcommunication node to the first communication node, receiving, by thefirst communication node, the second data from the second communicationnode based on the scheduling information.
 19. The operation methodaccording to claim 17, further comprising, when the receptionconfiguration information further includes information indicating avalid period during which transmission of third data is restricted,transmitting, by the first communication node, the third data to thesecond communication node after the valid period expires.
 20. Theoperation method according to claim 17, further comprising receiving, bythe first communication node, from the second communication node amessage including information indicating that the SCI including thereception configuration information is to be transmitted by the firstcommunication node, wherein the first communication node receives theSCI in response to receiving the message.